Steering apparatus



Nov. 16, 1943. E. A. MMURTRY STEERING APPARATUS Filed Nov. 14, 1940 3 Sheets-Sheet 1 41 771C 772m; ATTORNEYS Nov. 16, 1943.

E1 A. McMURTRY STEERING APPARATUS,

Filed Nov. 14, 1940 s Sheets- Sheet 2 INVENTOR.

dww w 77207 1,; AWORNIZZ Nov. 16, 1943. E. A. MOMURTRY 2,334,343

Y STEERING APPARATUS Filed Nov. 14,1940 3 Sheets-Sheet s Jaw Patented Nov. 16, 1943 UNITED STATES PATENT OFFICE,

s'raanmo. PPARATUS Edward A. McMurtry, Chicago, ru. Application November 1 4, 1940,,Serial No. 365,615

(cl. lac-79.2)

16 Claims."

The invention relates to steering apparatus and more particularly to a power drive for the steering mechanism of a self propelled vehicle or the like.

The invention comprehends a. novel power actuated mechanism operating in synchronism with the manual turning of the steering mechanism whereby to greatly minimize and relieve the operator of the manual efiort now required in steering an automotive vehicle. It is an object of the invention to provide power means I ment which can be quickly applied to. and used with the various standard steering mechanisms in use today on automobiles, trucks, busses and the like or can. be initially installed as standard equipment. The invention is so designed and constructed that should the power. actuating means fail, the vehicle may be controlled by manual operation. The invention further comprehends the provision of a power means. which is automatic but always under the control of the operator and which can operate only when the operatoris turning the steering wheel.

A further object is to provide a steering mechanism controlling the power means which is or lost motion between the steering wheel positive in action and in which there is no play and the vehicle wheels.

Another object is to provide a power means for assisting the operator in turning the steering wheels whereby the worm on the steering rod may. be of greater pitch than those employed with a purely hand operated device thereby lessening the amount of turning of the steering wheel.

' Further objects are to provide a construction of maximum simplicity, efliciency, economy and ease of assembly and operation and repair, and

such further oblects, advantages and capabilities as will later more fully appear and are inherently possessed thereby.

The invention further resides in the'construcv an automobile i having steering wheel 2 mounted tion, combination and arrangement of parts illustrated in the accompanying drawings, and

whileI have shown therein a preferred embodi-' ment, it isto be understood that the same is susceptible of modification and change, and comprehends other details, arrangements of parts, features and constructions without departing from the spirit of the invention.

In the drawings:

Fig. 1 is a fragmentary side view partly diagrammatic of an automobile equipped with a device embodying the invention.

Fig, 2 is a vertical-section of the steering apparatus of Fig. l, with certain parts being shown in elevation for convenience.

Fig. 3 is a vertical sectionof the lower end of the steering rod and some of the associated parts, someof the parts being shown in elevation.

Fig. 4 is an end view looking in the direction of the line t il of Fig. 2.

Fig. 5 is a view similar to Fig. 2 of another form of steering apparatus.

Fig. 6 is an enlarged perspective view of. the control member shown in Fig. 5.

In the embodiment of the invention shown in Figs. 1 to 4 of the drawings there is illustrated at the upper end of the steering "rod or shaft 3 which may be encased withinthe usual steering post, the rod or shaft having fixed or keyed to its lower end a worm d enclosed within a stationary housing 5. The worm i is in continuous mesh with gear segment 5 mounted in the hous- 'ing 5 on a shaft i, one end of which is polygonal and extends outside the housing where it is attached to lever arm 8 connected at its other end to rod 9 to operate the front wheel in of the car through steering knuckle H in the manner well known in the art.

. On the steering rod 3 and at each end of the worm 3 are thrust bearing assemblies comprislng loosely mounted pinions l2 and it on each sideof which are friction collars or washers l4 separating the pinions from the worm and from ball bearing retainers IE on the rod 3'and abutting at each end of the housing 5. Sufficient space is allowed between the worm and the ball bearing retainers whereby the thrust of the worm when, turned in one direction will frictionally clutch or clamp a pinion between the worm and a ball bearing retainer and rotatethat pinion while the other pinion idles on the shaft.

The'pi'ni'ons l2 and I3 are in continuous mesh with pinions I 6 and llkeyed to shaft'lfl in the shaft extends beyond the housing through a 20. Between the lever and the housing 5 a collar 2| is keyed to the shaft and on the other side of the lever is collar 2i having a flat side to key it to the milled part of the shaft. Spring 22 is placed on end IQ of shaft i8 and is held in place between the collar 2 I and one or more lock nuts 22 threaded on the shaft whereby the spring exerts pressure against collar 2i and the lever to frictionally and tensionally hold the lever between the collars 2 i' and 2i in such manner that this lever will rotate with the shaft i3 through a predetermined arc. Composition or other fric-v tion washers 23 are preferably provided on the shaft on each side of lever 20.

The free or outer end of lever is slotted (see Fig. 4) to receive a crank pin 24 on one end of the lever arm 25 which is fixed at its other end on the end of valve shaft 23 by means of set screw 27. Valve shaft 23 is attached to valve 23 in valve chamber 29 and extends some distance outside the chamber. In order to normally maintain the levers 20 and 25 in alignment pins or projections 30 vand 3i are provided on the chamber and lever 25 respectively and spring 32 is wound around valve stem 23 with its ends extending on each side of pins 30 and 3|. When the levers 20 and 25 are in alignment th projections or enlargements 33 on valve 23 are in position to close the ports 34 and 34 in the valve chamber. This valve chamber is also provided with ports 35 open to the atmosphere and 33 to which is connected one end of conduit or hose 31, the other end of which is connected to air pressure tank 38 suitably connected to a source of air pressure operated by the engine of the vehicle or by an independent motor as desired.

The ports 34 and 34" are connected by pipes or hose 39 and) to opposite ends of cylinder 4i in which is a piston 42 secured to one end of shaft 43 the other end of which is provided with a bearing journal to receive pin 44 on lever arm 8 of the steering mechanism. J When the steering wheel 2 is turned by the operator the thrust of the worm in one direction or the other forces it against and frictionally engages either pinion |2 or i3 to-thereby turn shaft i3, through pinion or II, in'one direction or the other. As the shaft l3 rotates it rotates levers 20 and 25, the force of spring 22 being such that it will create a friction between shaft l3 and lever 20 suflicient to overcome the'force of spring 32, and the valve 28 is turned to open ports 34 and 34 thereby permitting passage of compressed air or other fluid from tank 38 to cylinder 4| to move piston 42 in one direction or theother depending upon whether opening 34 or 34 is connected with the inlet port 33 through the arcuate slot formed between the projections 33, and in consequence push or pull against the arm 3 and rod 3 to assist in turning the steering knuckle ii and the front wheels.

- Pins 45 and 40 (Figs. 2 and 4) extend from the,

valve chamber to contact extension" on lever 25 to form stop members and allowmovement of this lever and. the valve through a predetermined are Just sufficient to open the valve ports 34 and 34 so that upon discontinuance of the manual turning of the steering wheel 2 the valve will have to turn through a small arc to close the portsd cut 01! the a supply. stopping the upper part of the housing 5. One end It of said power means.- The shaft i8 will continue to turn but the lever 20 being but frictionally connected thereto will not move after the extension 4l of lever 25 contacts the stop members 45 or 43.

Upon termination of movement of shaft l3 spring 32 will immediately act to return the levers 20 and 25 to their aligned position to close the valve. In doing this, spring 32 will turn lever 20 and shaft l3 slightly, the pinions l2 and i3 being freely rotatable on shaft 3 when the worm thrust is relieved and will not then rotate the pinions i8 and I1, and will permit this movement of shaft i3 and lever 20. This-is so whether or not the power means is strong enough to continue turning the worm, as such operation of the worm will not exert a thrust which redevice will operate for just an instant to release the thrust friction caused by the motion of the steering wheel, thus releasing the friction holding pinion, l2 or i3 as the case may be, and .the control valve will be returned to neutral by the action of spring 32, cutting off the power.

If the power device is of low power and is not quite able to move the vehicle wheels, the operator may stop the movement of the steering wheel at any point, and this will hold the wheels in a given position, but in this case the power may remain on until a slight reverse of the motion of the steering wheel will release the friction and then the power will be cut oil by action of spring 32. If the motion of the steering wheel is continued inthe new direction the thrust friction will cause the opposite'control action and Assume. that the wheels of the vehicle strike a rut with suilicient force to cause them to be moved suddenly in the same direction as they are being turned, and thus, momentarily, lead the power device and the motion of the steering wheel. Under these conditions the thrust fric- 1 tion holding the control valve open, will be released and the power cut off for aninstant, until the continued turning of the steering wheel by the operator restores the thrust friction thus applying power again, provided the operator has been continually turning the wheel.

Under no conditions can the power device or. the movement of the vehicle wheel assembly) lead the control motion of the steering wheel without having the power momentarily cut off .until the continued action'of the steering wheel causes it to be-restored.

Under no conditions can the power device be put into operation in such a way as to lead the motion of the steering wheel and lock the wheels at theend of the complete turn in either direc- Of course it is understood that, at all times.a slight reversal of movement of the steering wheel will release the thrust friction restoring the valve to neutral and cutting of! the power or, in the case of appreciable movement in the ne direction, reversing the power.

In Figs. and 6 is shown another mechanism for operating or actuating the power means and helps to illustrate the importance of the thrust of the worm to accomplish this.

In this important and simplified formlof theinvention, the steering rod is provided with the usual worm 4 in mesh with gear segment 6 and operating arm 8 through shaft I. Housing 5'- is provided for the worm and segment. Adjacent and connected to (or integral with this housing) and also surrounding the shaft 3 is housing I in which is located the mechanism for actuating valve 28 in chamber 29. This mechanism comprises a sleeve or collar 48 keyed to shaft 3 and on each side of which'and also surrounding the shaft are thrust bearing assemblies including collars 49 between which and the ends of the chamber 5 are ball bearing retainers I5. The collars 49 are provided with perimetric grooves 50- for receiving split rings 5i at the ends of arms 52 of yoke 53. These split rings are of resilient material and are so.-made as to frictionally engage the grooves of collars 49 with sufil'cient tension that movement of either collar will cause it to carry, and rotate with it, the split ring and yoke.

.Yoke .53 extends between the forked ends 54 V of arm or lever'25'e whichis keyed to or otherwise secured upon valve stem 26 of-valve 28 in chamber 29. This valve is operated by the arm 25- in the same manner as it is operated by arm or. lever 25 in the construction shown in Figs. 1-4.

Thev operationof this mechanism is-substan tially the same as that shown in Figs. 1-4. When the steering wheel 2 ,is turned the worm 4, in operating the segment 6, willcause a thrust of the rod or shaft 3 in one direction or the other, thereby causing a frictional engagement orclutching connection between the sleeve on collar-48 and one or the other of the collars 49 whereby to lock the collar 49 between the sleeve 8 and a thrust bearing i5, causing the collar 49- to turn with the steering rod... The collar will'carr'y withit the yoke 53, moving the lever 25"- in one direction or the other to open the valve 28 in the valve chamber 29 and causin the power means to operate and assist lathe movement of the arm 8, and steering mechanism connected to it and'the steering wheels, whereby to-turn the latter. As 'is'shown, spring 32 and arms 30 and 3! are provided on the valve stem 26 and valve chamber 29 and lever 25 in. the

same manner as shown in Figures 1-4 to maintain the valve in closed position. The lever 25 is also provided with extension 41 and the valve chamber is provided with stop members or projections 45 and 66 to prevent the lever 25 from turning through an angle or are suflicient to open the valve fully.

As shown in both embodiments, thecylinder 41 is preferablymounted for slight rotation on bracket 55 suitably attached to the vehicle frame.

It is apparent that the other'types of controls and other sources of power, such as vacuum from the manifold, oil, or the like could be used in place of the compressed air, or that other power means such as electricity could be .used and that the device is capable of use with devices other than automobiles without departing from the spirit of the invention. 1

Having thus disclosed the invention I claim:'

1. Vehicle steering apparatus comprising a steering wheel and rod, a worm on said rod, a member operated by said worm, an arm connected to said member for moving the wheels of the vehicle, power-means connected to said arm to assist in its movement, a member adjacent each end of the worm and either member adapted to be clutched to and rotatable with the worm depending upon the direction of thrust of the worm, a shaft adjacent said worm, pinions on the shaft and connected to the members so as to be moved thereby when manual operation of the steering wheel causes a thrust of the worm, a valve for actuating said power means and means connecting said pinions and valve whereby movement of a pinion upon manual movement of the steering wheel will open said valve.

2. Vehicle steering apparatus comprising a steering wheel and rod, a worm on said rod, a member operated by said worm, an arm connected to said member for moving the wheels of the vehicle, members frictionally engageable by the worm when manual movement of the steering wheel causes a thrust of the worm, power means connected to said am to assist in its movement, a shaft adjacent said worm, pinions on the shaft and adapted to be moved by said members, a valve for actuating said power means and means connecting said shaft and valve whereby movement of the worm by manual movement of the steering wheel will cause it to engage a pinion to open said valve, and means for closing said valve upon cessation of manual movement of said steering wheel.

3. Vehicle steering apparatus comprising a steering wheel and rod, a worm on said ro'd, a segment operated by said worm, an arm connected to said segment for moving the wheels of the vehicle, members frictionally engageable I and movable by the worm upon manual move-' ment of the steering wheel, power means connected to said arm to assist in .its movement, a shaft adjacent said worm, pinions on the shaft and adapted to be moved by one of the members upon said manual movement of the worm, a valve for actuating said power means, ,means connecting said shaft and valve whereby movement of a pinion will open the valve, and a spring adaptedto close the valve upon discontinuance of the thrust friction between the worm in said housing with one end extending beyond said housing, pinions keyed to said shaft and in; meshwith the worm pinions, valve actuating means controlled by said shaft, and means for closing the valve upon discontinuance of the "worm thrust.

5.,Vehicle steering apparatus comprising 'a steering wheel and rod, a worm on the rod, thrust bearings mounted on said rod, a member operated by the worm, an arm connected to the member for moving the wheels of the vehicle, power means for assisting in such movement,

.means adapted to frictionally ,engage either of said thrust bearings and rotate with the rod upon manual movement of the steering wheel, a valve on said power means and havinga valve shaft actuated by said last mentioned means and a spring connected to said valve shaft and adapted to close said valve upon discontinuance of said worm thrust.

6. Vehicle steering apparatus comprising a steering wheel and rod, thrust hearings on said rod, a worm on said r'od, a segment operated by said worm, means connected to said segment said members for opening said valve and means associated with the valve shaft for closing the valve upon discontinuance of said worm thrust.

7. Vehicle steering apparatus comprising a steering wheel and rod, a worm on said rod, thrust bearings associated therewith, a segment operated by said worm, means connected to said segment for moving the wheels of the vehicle, power means for assisting in said movement, a

I member keyed to the rod and adjacent the worm, means on each side of said member associated with said thrust bearings and adapted to be clutched to and rotated with the member by friction arising from the thrust of the worm resulting from manual turning of the steering wheel, said means being connected to said power means for actuation of said power means.

8. Vehicle steering apparatus comprising a steering wheel and rod, a worm on said rod, a segment operated by said worm, means connected to said segment for moving the wheels of the. vehicle, power means for assistin in said movement, a sleeve adjacent the worm and keyed to the rod, collars on the rod on each side of the sleeve, either of which is adapted to be clutched by and rotate with the sleeve depending upon to said segment for moving the wheels of the vehicle, power means for assisting in said movement, a sleeve adjacent the worm and keyed to the direction of thrust of the worm resulting from manual turning of the steering wheel, a valve for actuating the powerrmeans, an arm eonnected to said valve, and means connecting said arm to said collars whereby movement of a collar will move the arm to open the valve.

steering shaft, a worm fixed thereon and sub- 9. Vehicle steering apparatus comprising a steering wheel and rod, a worm on said rod, a

, segment operated by said worm, means connected by and-rotate with the sleeve depending upon the direction of thrust of the worm resulting from manual turning of the steering wheel, a valve for actuating the power means and split rings frictionally engaging the collars and attached together and connected witlfthe valve, whereby movement of a collar will open the valve. i '10. Vehicle steering apparatus comprising a steering wheel and rod, a worm on said rod, a

segment operated by said worm, means connected th rod, collars on the rod on each side of the sleeve, either of which is adapted to be clutched by and rotate with the sleeve depending upon the direction of thrust of the worm resulting from manual turning of the steering wheel, a valve for actuating the power means and having a valve shaft, an arm on said shaft and split rings frictionally engaging the collars and rigidly attachedv together and connected with the valve arm wherebymovement of a collar will move the arm to open the valve, means for limiting the movement of the arm and means for returning the arm to close the valve upon discontinuance of the worm thrust.

ll. Vehicle steering apparatus comprising a steering wheel and rod, a worm on said rod, thrust bearings associated therewith, a segment operated by said worm, means connected to said segment for moving the wheels of the vehicle, power means for assisting in said movement, a. member keyed to the rod and adjacent the worm, means on each side of said member and between said member and thrust bearings adapted to be clutched to and rotated with the member upon the thrust of the worm resulting from manual turning of the steering wheel, said means being connected to said power means for actuation of said power means, and means for shutting off the power means upon discontinuance of the manual turning of the steering wheel.

12. Vehicle steering apparatus comprising a steering wheel and rod, a worm on said rod, a segment operated by said worm, means connected to said segment for moving the wheels of the vehicle, power mean for assisting in said movement, a sleeve adjacent the worm and keyed to the rod, collars on the rod on each side of the sleeve, either of which is adapted to be clutched by and rotate with the sleeve depending upon the direction of thrust of the worm resulting from manual turning of the steering wheel, a valve for actuating the power'means, an arm on said valve, and means connecting said arm to said collars whereby movement of a collar will move the arm to open the valve, an means for closing the valve upon cessation of manualturning of the wheel and the consequent thrust of the worm.

13. Power mechanism for augmenting the manual turning movement in either direction of manually controlled steering apparatus and the like and in which the apparatus is provided with a jected to a thrust when manually rotated in either direction, a tooth member in mesh with the worm and a connection from the member for turning the wheels of a vehicle, comprising a pair of collars loose upon the shaft but adapted to be and'controlled by the control means and conually controlled steering apparatus and the like and in which the apparatus is provided with a steering shaft, a worm fixed'thereon and subjected to a thrust when manually rotated in either direction, a tooth member in mesh with the worm and a connection from the member for turnin the Wheels of a vehicle, comprising a pair of collars loose upon the shaft but adapted to be clutched thereto upon the application of thrust to the worm, means frictionally carried by each collar, power control means connected to the first mentioned means and responsive to thrust in but one direction, and a power unit associated with and controlled by the control means and connocted to the steering apparatus tor relieving the operator of the manual effort and physical fatigue encountered in steering a power propelled vehicle.

15. A reversible power mechanism for assisting the turning movement or manually controlled apparatus including a manually rotatable shaft and a worm secured thereon and subjected to an end thrust each time that the operator rotates the shaft, comprising a pair of members normally loose upon the shaft but adapted to be clutched for rotation therewith each time the worm is subjected to an end thrust, a split ring associated with each collar and rotatable therewith, and a power unit connected to the manually controlled apparatus and including valve mechanism actuated by turning movement in either direction, and means for automatically and positively disconnecting the power unit upon the operator ceasing turning effort in either direction.

16. Power mechanism for augmenting the manual turning movement in either direction of manually controlled steerin apparatus and the like thrust tothe worm, members frictionally engag ing said collars for rotation therewith, an actuating lever in the path of said last mentioned members, a valve actuated by said lever for sup plying fluid under pressure to said mechanismI and a power unit receiving-the fluid under pressure and connected to the steering apparatus for relieving the operator or the manual eflort and physical fatigue encountered in steering a power propelled vehicle.

EDWARD A. McMUR'mY, 

